DISCUSSION
The paranasal sinuses are in close anatomical proximity to vital and
delicate structures, such as the skull base, orbit, internal carotid
artery, and optic nerve. Broad and detailed anatomical knowledge is
essential for surgeons to perform safe and effective
procedures.12
With the advent of intraoperative imaging, surgeons have acquired a
greater operative domain. Undoubtedly, a thorough knowledge of anatomy
is essential to nasal surgeons. Nevertheless, malformations, previous
surgeries, and nasal polyposis can make orientation in the surgical
field difficult, even for an experienced surgeon.15
Vreudenburg et al. and Dalgorf et al. found a reduction in the
likelihood of total, major, and orbital complications in complex ESS
procedures with the use of IGS. They included case-control and cohort
studies in their systematic reviews, while the current review did not.
The small number of clinical trials on the subject was a limitation of
our findings; hence, the low incidence of complications in
ESS.19,33
Tschopp et al. conducted a case-control study comparing ESS with and
without image guidance, and although they did not reach statistical
significance for the reduction of complications, they calculated the
necessary sample size to achieve significant conclusions regarding the
prevention of complications based on their own complication rate. In
their analysis, a sample size of at least 880 was necessary to draw
reliable conclusions on the subject.34
There is a lack of data in the literature regarding the estimated blood
loss. Metson et al. in their prospective cohort found similar data to
Singh, with 178.4 ± 18 mL in the IGS group and 149.4 ± 20.1 and no
statistical significance (p=0.31).35 Conversely,
Tschopp et al. reported 180 ± 124 mL (IGS group) and 201 ± 198 mL (ESS
group).34
Despite the limited number of studies that conducted quality of life
assessments in patients with CRS who underwent ESS with and without IGS,
the evidence suggests a greater improvement in the quality of life of
patients operated on with navigation. Due to the heterogeneity of the
outcome measures used in the literature, it is difficult to combine or
compare data from different studies.27,28
One of the concerns since the inception of image guidance technology is
that it would lead to a significant increase in the operative time and
therefore increase the procedure cost. Evidence from the literature
suggests that IGS does increase the preparation time, but it may lead to
a reduction in the incision to suture time, thereby compensating for the
overall operating room time.29,31,34,35
In addition to the possible decrease in the complication rate for ESS,
the possibility of opening more of the diseased paranasal sinuses is an
important question. This review provides important evidence that IGS is
more effective than conventional ESS. To the best of our knowledge this
is the first paper to present this evidence. Whether this may lead to
better patient-reported outcome measures should be the subject of future
research.28,31,32
The small number of high-quality studies with a low risk of bias is a
limitation of this review. New clinical trials are important to better
elucidate the role of image guidance in endoscopic surgery of the
paranasal sinus.